This invention relates to a racket having a stringed hitting surface surrounded by a frame with a hand-grip shaft to which a hand-grip formed of a pair of half-shells is attached, especially a tennis racket.
A racket, especially a tennis racket, of this type is known from DE-OS No. 21 06 800. The grip of this known tennis racket consists of a grip shell that is preferably formed of two half-shells, with said grip shell being firmly arranged on the shaft with an insert of a shock- or vibration-damping material being placed in-between. The two half-shells are joined together by screws which penetrate into the shaft through boreholes which are larger than the screw diameter, so that the screws do not come in contact with the walls of the boreholes. Therefore, in order to ensure that the grip does not slip on the shaft, the insert must be pressed firmly to the shaft by means of the screws. This measure has the purpose of avoiding the effect of hard impacts being transferred to the arm of the player in a undampened manner. However, the distance of the hand-grip from the hitting surface cannot be adjusted with such a known racket.
It is an object of the invention to develop a racket, especially a tennis racket, which is constructed such that the grip can easily, preferably also during the game, be moved toward or away from the hitting surface.
This objective is achieved in accordance with preferred embodiments of the present invention by utilizing half-shells of non-compressible material, but connecting them by elastic grip means which holds the half-shells firmly to the frame shaft, yet still enables the hand-grip to be moved longitudially therealong via an adjusting device. The adjusting device is secured to the hand-grip in a manner precluding axial and radial movement relative thereto and is interconnected with an end of the racket frame shaft in a longitudinally adjustable manner.
By using half-shells made of a hard material, or using a hard interior wall in the case of half-shells made of a soft compressible material, and by elastically fitting them together to form the hand-grip, by means of one or several elastic strips, an elastic tube or elastic tube sections, the grip may still be moved on the shaft even if the contact pressure of the half-shells is relatively high, by means of the adjusting device. The known grips, where the half-shells consist of a soft, preferably foamed and thus volume-compressible material or are connected with the shaft in a form-fitting manner, do not offer this possibility.
It is known to develop the grip of tennis rackets so it can be lengthened. Thus, on the basis of DE-PS No. 942 075 or DE-OS No. 20 29 533 it is known to slide and lock a sleeve-shaped grip on the shaft using a prestressed inside pressure spring. After the lock is released, the sleeve bounces back and causes an increase in the length of the grip. In this case, the lengthening or the shortening of the grip is always constant, i.e., intermediate positions are not possible.
A manual change of length without the use of a spring is known from De-OS No. 20 30 998. In this case, this change is achieved by the screwing-on or unscrewing of special shaft or grip parts of predetermined length.
All of these developments, in practice, are not particularly well suited for use during playing and have, therefore, not been successful on the market.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only several embodiments in accordance with the present invention.